Research indicate that over one-third of cancer patients experienced cancer pain, which is known as a major reason leading to lower quality of life of the patients.In this present study, the investigators aim to design, develop, and test the feasibility of a low cost, conveniently implemented mobile application to facilitate real-time pain recording and timely intervention among Chinese cancer patients with pain. This system evaluate real-time pain and Karnofsky Performance Status（KPS）scores for quality of life, and to generate an action plan to visit the physician or to adjust pain medication dosage when the pain threshold is reached. The investigators study is to test this system's effectiveness.